Suicide Risk among Cancer Patients: Experience at One Medical Center in Japan, 1978–1994

In order to identify the risks, methods and locations of suicide among Japanese cancer patients, we followed up 23,979 cancer patients aged 15 years and older, who were newly diagnosed at one medical center between 1978–94. Suicide risk was evaluated by comparing the observed number (O) with the expected number (E), which was calculated from the suicide mortality rate among Osaka residents. By the end of 1994, there were 48 suicide death among 109,374 person‐years of follow‐up. Suicide risk was significantly increased within the first five years following cancer diagnosis (male: O/E=1.62, 95% confidence interval (CI)=1.03–2.43, female: O/E=2.13, 95%CI=1.22–3.47), and decreased to unity after five years had elapsed following the cancer diagnosis. Patients in their fifties (O/E=1.93, 95%CI=1.48–4.37), diagnosed between 1978–85 (O/E=1.93, 95%CI=1.19–2.95), having remote metastasis at their initial diagnosis (O/E=4.66, 95%CI=2.12–8.84), the site being in the female genital organs (O/E=3.58, 95%CI=1.54–7.06) or in the male genital organs (O/E= 5.86, 95%CI= 1.58–15.05), had a significantly higher suicide risk within five years following cancer diagnosis. The highest suicide mortality was observed between the third and fifth months after cancer diagnosis (O/E=4.35, 95%CI=1.87–8.58); most of these suicides (7/8) occurred soon after discharge from hospital. Among the 39 patients who committed suicide within five years after their diagnosis, the most common method among those who took their lives while in hospital was by jumping to their death (10/16), and that among those who committed suicide in other locations was by hanging (14/23). These findings indicate that Japanese patients with cancer run the highest risk of suicide soon after having been discharged from hospital. Clinicians should assess cancer patients' psychological distress and potential risk of suicide before approving discharge from hospital.